Apparatus for wireless signaling.



B. A. FESSENDEN.

APPARATUS FOR WIRELESS SiGNALING.

APPLlCATION FILED SEPT. 16, 1907.

1 1651862. Patented Dec.28,1915.

3 SHEETS-SHEET I.

WIT/YISSIS j/V Iii/V7017;

R. A. FESSENDEN.

APPARATUS FOR WIRELESS SIGNALING.

APPLICATION FILED SEPT. 16, 1907.

1,165,862. Patented De0.28,1915.

3 SHEETS-SHEET 2T WIT/VX5515.- wy 7 ,9

R. A. FESSENDEN.

APPARATUS FOR WIRELESS SIGNALING.

APPLICATION FILED SEPT. 16, 1907.

Patented Dec. 28, 1915.

3 SHEETS-SHEET 3.

Q m ig T MM UNITED STATES PATENT OFFICE.

REGINALD A. FESSENDEN, OF BRANT BOGK,- MASSACHUSETTS, ASSIGNOR, BY MESNEASSIGNMENTS, '10 SAMUEL M. -KINTNER, OF PITTSBURGH, PENNSYLVANIA, ANDHALSEY M-..BARRETT, OF BLOOMFIELI), NEW JERSEY, RECEIVERS.

APPARATUS FOR WIRELESS SIGNALING.

Specification of Letters Patent.

Patented Dec. 28, 1915.

My invention relates especially to high frequency electricalOscillations and to means for generating electro-magnet1c waves.

The primary object of the invention is to provide for more efficientproduction of high frequency oscillat ons and electromagnetic waves, andin particular improve the construction and operation of apparatus forthis purpose.

T he objects and advantages herein set forth are conveniently attainedby the construction illustrated for example in the form of the generatorshown in che accompanying drawhags.

1 lo a see i f the axis, machine .ures of my invention. bial diagramillustratng a ing the armature o r- 3 IS a fragmentary plan viewof theface of a revolving inductor pole If prefer to use.

Fig. 4; is a perspective view of convenient means for mounting themachine for use on ship board or other places where the support isunstable. Figs. 5 and are respectively a partial section and a partialside elevation showing a modified form of armature construction.

Heretofore difficulty has been found in obtaining a large output fromhigh frequency generators used for the production of electro-magneticwaves, on account of the difiiculty of obtaining the narrow air-gapnecessary, and producing a sufiiciently strong magnetic field andobtaining a sufficiently high frequency. My invention overcomes thesedifiiculties as well as others, as will hereinafter appear.

Referring first to Fig. 1, there is provided the rotating inductor disk11 shown in section, mounted upon a shaft 22 and preferably driven bysome high speed motor such as a De Laval steam turbine of the typeillustrated in Fig. 4. The disk 11 is preferably turnedfrom a singlepiece of metal and preferably made of nickel vana-- dium steel. Thecasing 21 should have supports adjustable in all directions so that thedisk may be accurately centered when in motion, in order to center thefield of the generator. This is very important because the axle of thedisk 11 must have flexibility, either in itself or in its mounting, andtherefore if adjusted when at rest, its position will change when inmotion and unless the disk is adjusted while in motion, the eliioiencyis much reduced. Any kind of adjustmen should be capable of extremeaccuracy. be arranged as in Fig. i by adjusting screws :1. The centeringmay also he accomplished by means of a bearing 38 adjustable in positionby means of screws 39 in the supporting ring 23 supported on springs 40as shown in Fig. 1. The disk in rapid rotation of course tends to assumeits own grav ty center. llhe sides of the per 1 12 or die disk 11 areprefndicated at Fig. 3, and filled up witi some nonnce, in order topresent a surface and reduce the .i wise the whole machine may bemounted in a vacuum for the same purpose, as is The revolving disk 11 isinclosed in a frame or casing 1- 21, and to' the part 21 are attachedarmatures 19, 20 of insulating material on opposite sides of theperiphery 18 of disk 11 and adjustably mounted upon the frame, as bythreads, so that the armature winding may be moved and may approach moreclosely the slotted periphery 18 of the disk than the laminated rings15, 16, which are also mounted in the casing over the field coils 12,13. These coils energize the magnetic circuits 14, 15, 18, 11, and 17,16, 18, 11. The rings 15, 16 are preferably laminated in order to avoideddy currents.

Th armature winding is indicated in Fig.

2, as formed by the conductor 24. This figure also illustrates anotherarmature winding, on rings 19, 20 formed by the conductor 25, which hasa transmitter 26 in series with it. By putting this transmitter intoaction the currents in the winding 25, affect the strength of thecurrents in winding 24, and if the winding 24 be connected to the groundand to an antenna, in the usual man ner, electrical signals may thus beproduced.

It has been found by experiment that by using the unsymmetrical air-gapabove described much higher voltages and outputs, and higherefficiencies are obtained, and this is one of the principal features ofmy invention. The operation of the device will be evident to thoseskilled in the art.

While the applicant cannot fully state the reason of the action, it hasbeen proven by experiment that a larger output is gained by thisarrangement. Possibly it is because the winding being nearer the oneside of the gap causes a concentration of the lines of force at the timeand place where they are cut.

In the use of a high speed generator for wireless signaling on shipboard for example, or where the support is unstable, the gyratory effectof moving the rotating disk out of its plane of revolution might resultin displacing the relative position of parts and cause the disk to cutthe armature 19, 20. In order to prevent this and increase theefiiciency of operation, in addition to using a device for accuratelycentering the revolving inductor while it is in motion as abovedescribed, it have shown in Fig. t a desirable mounting for the wholemachine and the driving motors. In this figure the steam from supplypipe 31 is led through a reducing valve 32 in order to keep the pressureconstant, and after passing through the two De Laval turbines 29, 30,may exhaust through pipes 33, 34, into base 35. These turbines and thegenerator 28 are all, attached to the pivoted frames 36, 37 of agyroscopic mounting supported in the base 35.

It will be understood that in a machine involving such high speed ofrotation, the mounting must be able to accommodate itself to the movingelement, and it has been found that not only on shipboard but even instationary plants the machinery'is much less liable to shock and wear byallowing the bearings freedom of motion. For this reason the mountingshown in Fig. lis Very advantageous, and it is especially soon ac countof the necessity of adjusting the parts While the rotary inductor is inmotion, as above described. lit will be understood that ll may eitheruse a double armature as in Fig. 1- or a single armature between doublesets of teeth on the inductor as in Figs. 5 and 6. g

in Figs. 5 and e, 42, as, 44, 45, 4e, 51, 5a are metal rings forsupporting the armature. 48 is the armature which is made in numeroussections of boxwood or other suitable material, having the slots 56formed in them thus leaving the projections 55 (shown sidewise in Fig. 5and face View in Fig. 6) between the slots. The winding a9 is Wound amenace in a recess in the projecting portion 55 as shown. Any suitablefield construction may be used for this armature, which is preferablyplaced unsymmetrically and near the inductor projections in the air gapbut the field circuit may be as shown in Figs. 5 and 6, where 50 is therevolving part of the magnetic circuit and 54: isthe field coil. Thismethod of constructing the armature obviates a very serious diflicultymet with in the usual form of construction, a. e., warping. This is amatter of small importance in ordinary machines, but with high frequencymachines of the type here described a warping of a few ten thousandthsof an inch per inch reduces the output, by its cumulative action, to asmall fraction, by reason of the windings neutralizing each otherseffects. Even armatures constructed of resined maple wood warpsufficiently to reduce the output to one quarter or less of what'itshould be. By thus constructing the armature in small sections clampedbetween metal rings, and so supported that each section can expandindependently it is possible to obtain the grain running always radiallyand to make armature sections interchangeable, and to obtain the fulltheoretical output.

l have found by experience that the above mentioned details ofconstruction are of supreme importance, though I am not prepared to sayin all cases why the superior results are attained. It will beunderstood that the feature of telephoning by directly varying thecurrents in the armature Winding, is not claimed herein, but will becovered in a separate application; the present case being limited to theconstruction of the generator itself.

Having thus described my invention, what T claim as new and desire tosecure by Letters Patent, is the following:

1. A high frequency current generator having elements forming a magneticcircuit 110 with an air gap, a toothed movable inductor traveling insaid gap,and an armature Winding located in the gap nearer to theinductor than the side.

2. A' machine for producing high fre- 11 quency oscillations comprisingelements forming a magnetic field circuit with an air gap, a rotaryinductor and an armature in the air gap Whose winding is placedunsymmetrically in the space between elements 1 of the magnetic circuit.

3. In a dynamo, the combination of a rotating inductor having anundulating magnetic face, elements forming a magnetic field with an airgap therein and armatures hav- 125 ing windings in the gap placed nearerto the inductor than to the side of the air gap.

4. Tn a high frequency dynamo, the com bination with a field coil and acasing forming part of the field circuit, of a rotating in- 180 ductorand a plurality of armature rings adjustably mounted in the casing neartne rotating inductor.

5. In a dynamo, the combination of a frame forming part of the fieldcircuit, a field coil and an armature ring in the air gap, a rotatingtoothed disk inductor, and an armature Winding mounted between the ringand disk.

6. In a dynamo the combination of a field frame, a field coil, a pair ofarmature rings, a rotating inductor and a pair of armature windingsmounted between said inductor and the rings located close to the sidesof the inductor.

7. A high frequency current generator comprising a field circuit with anair gap, a rotary inductor traveling in the gap, two stationaryarmatures, and a mounting having means to adjust the relative positionsof the inductor and armatures.

8. In a high frequency dynamo, the combination of elements forming amagnetic field circuit with an air gap, a revolving inductor therein anda plurality of armatures mounted in the air gap and having means foradjustment of the armatures to vary their distances from said inductor.

9. A high frequency dynamo comprising the combination of a revolvinginductor and a plurality of armatures mounted adjacent thereto and meansfor adjusting the armatures to vary the positions of their windingsrelative to the inductor.

10. An alternating current generator having .an armature support made ofinsulating material in numerous sections, and metallic rings clampingand adjustably supporting said sections so as to allow said sections toexpand independently and yet be adjusted as a Whole.

11. A high frequency alternator comprising a casing, two armature ringsmounted in the casing with means to adjust their distance apart, arotary inductor and flexible supports for the inductor having means toadjust the position of the center of gravity of the inductor relative tosaid armatures.

In testimony whereof, I have hereunder signed my name in the presence ofthe two subscribed witnesses.

REGINALD A. FESSENDEN.

Witnesses:

JESSIE E. BENT, ADELEINE WOLEVER.

